This is a special report from ABC news. Hello everyone I'm Tanya Rivero in New York with an ABC news digital special report new. Tied to the Boston bombing suspects we now know evil regime to adoption -- -- being investigated. For his connection. And -- For his connection and the older brother camera -- connection to a triple homicide in Massachusetts in 2011. Early this morning an FBI agent shot and killed the -- and after being allegedly attacked by him. Right now we're gonna bring an ABC's -- -- -- heat for more on these developments hi there Aaron. Tanya good morning good afternoon the the the the killing of to this whole investigation of the Boston Marathon case because authorities have now gone up and down the I 95 corridor. The latest investigation taking them to Orlando Florida the apartment of -- production of -- Friends say was targeted almost from the beginning because he's tension and because he had been in contact with temperaments are -- In the weeks prior to the marathon attacks so authorities wanted to know what his connection was come to find out. That he was about to confess were told. To an unsolved triple homicide in Waltham Massachusetts and 2011 that had also been -- contaminants are nine but at some point during that confession. Law enforcement officials tell ABC news that to dock -- went crazy became violent may have had a nice. And at that point he was shot dead either by the FBI agent who felt threatened or by Massachusetts state police who -- a company. Stepping back up for second -- fill us in on this triple homicide we've heard before. That camera -- was being investigated in association with this homicide but can you fill us in on the details. Well one of the victims in that to triple homicide in 2011 in Waltham Massachusetts was somebody. Who was said to be one of contaminants are knives friends that the case was. Fascinating to two to the police in the community not only because it was -- solved but also because. That the bodies were found with marijuana kind of rubbed into them -- rubbed against them. -- and authorities had nothing to go on but as. A more was learned about the victims and their connections to mixed martial arts and then as feminine sometimes connection to mixed martial arts and neighboring into -- -- connection to mixed martial arts. All started to come out. Police were trying to put all these pieces together. Now is my understanding that agents are saying he was at the agent that shocked. Ibrahim was being staffed by tens -- -- 94 what kind of weapon. Well those details weren't exactly clear where we're told initially the FBI said in his statement that the FBI. Agent who is doing the interview felt threatened and that he pulled a gun and shot and killed Sadat said in a subsequent statement. Did that the question of who shot to dostum was left open it was not specified so it could have been the FBI agent. Could've been the Massachusetts state troopers or other law enforcement officials who had accompanied the FBI agent to Orlando for this interview. Now whether -- -- -- actually pulled a knife we're told he was armed with a knife. And became violent but we don't know the specifics of the altercation that took place but. We've spoken with some neighbors who heard something and then they heard the gunshots what and what -- the neighbors said they heard yelling what did they. Yet -- where we talked to one neighbor a guy by the name -- Jared Morse who said that he had been watching basketball and and at some point. Heard -- some kind of confrontation before he heard. A couple of banks. Went outside to try and ascertain what was going on but was told by police to get back into his house. And he simply said it was crazy to think that there was some connection to the marathon attacks living and is a part. And conflict and now and do investigators have any evidence right now linking at least -- lend to these these homicides this triple homicide. Whether there and they seem to be getting close -- because I hear he knew one of the victims were told. -- -- he had also said to have become a bit more devout and was said to be unhappy that his younger brother Joseph hearts are -- I have. Had developed something of a marijuana habit that's what college friends had told us about Joseph -- -- of and then these bodies were found in 2011 and Waltham Massachusetts would marijuana kind of sprinkled on them. Yes I remember reading those that are -- -- -- that I guess at the time investigators thought it was a perhaps a drug related crime and it ended in -- was maybe there was a supplier advise you know who goes on of those details have not come out. And prosecutors have not officially linked to any of these these people to this unsolved killing -- -- officially an unsolved. Triple homicide but but authorities apparently are are getting close and -- -- -- ship was. Apparently in the middle -- confession and it also seemed to be some sort of link in the Marshall mixed martial arts community isn't that right one of the victims was also in that community that's right that's how we knew temperaments -- -- have been any bring him to not have also involved in mixed martial arts -- temperaments are -- of from. From Boston so all these things are just now starting to come together but the FBI still. Has not released definitive information about what it is they were there were about to get from him. And and what ultimately led to -- to a shooting. Lots of pieces of the puzzle yet to emerge -- thank you Aaron -- -- for all of that. They went on for more on the latest developments on this shooting investigation in Orlando but it abcnews.com. On -- ribeiro in New York. And this has been an ABC news digital special report. This has been a special report from ABC news --

This transcript has been automatically generated and may not be 100% accurate.

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